﻿using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using System.IO;
using System.IO.Compression;

namespace FuckCaptcha
{
    public class Service_Captcha
    {
        List<CharInfo> words_ = new List<CharInfo>();
        public Service_Captcha()
        {
            byte[] bytes = new byte[] { 
                    0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0xc5, 0x58, 0xd9, 0x92, 0x13, 0x31, 
                    0x0c, 0x94, 0x9e, 0x93, 0x0c, 0x61, 0x97, 0x2f, 0xe1, 0x58, 0xe0, 0x91, 0x9b, 0x82, 0x62, 0x0b, 
                    0x58, 0xee, 0xff, 0xff, 0x10, 0xd8, 0xcc, 0xc8, 0xea, 0x96, 0x6c, 0x8f, 0x13, 0x48, 0xe1, 0xaa, 
                    0x4d, 0x46, 0x96, 0x6d, 0xb5, 0x8e, 0x96, 0x67, 0x73, 0x7f, 0x3b, 0x09, 0x0e, 0x25, 0x41, 0x49, 
                    0xa3, 0xae, 0xd7, 0x5b, 0xa9, 0xa8, 0xd5, 0xb4, 0x76, 0x02, 0x6a, 0x5c, 0x52, 0x94, 0x54, 0xed, 
	                0x18, 0x5a, 0x7f, 0x18, 0x00, 0x00, 0x84, 0x07, 0x1b, 0x80, 0x4a, 0x9a, 0x08, 0x35, 0xb8, 0x81, 
                    0x50, 0xe7, 0xad, 0xbe, 0xc4, 0x8e, 0xb1, 0x4f, 0x2d, 0x5f, 0xba, 0x80, 0xbb, 0xfd, 0x9a, 0xad, 
	                0x19, 0x36, 0xe5, 0xad, 0x87, 0xf1, 0x10, 0xc0, 0x8d, 0xc6, 0x50, 0x40, 0x52, 0xf8, 0xb3, 0x98, 
	                0x2c, 0xd6, 0xec, 0x59, 0xe7, 0x0d, 0x3e, 0x0f, 0x93, 0x3e, 0x1d, 0x02, 0x7a, 0x18, 0x8f, 0xb6, 
	                0xc7, 0x46, 0x4e, 0x01, 0xa3, 0x96, 0xdc, 0x3a, 0x20, 0x77, 0xbf, 0x2c, 0x24, 0xe4, 0x80, 0xa9, 
	                0x20, 0x14, 0xe5, 0x2d, 0xb5, 0x68, 0xc9, 0x55, 0x89, 0x23, 0x96, 0x82, 0xaa, 0xba, 0x58, 0xa6, 
	                0x03, 0x38, 0x71, 0x4b, 0x29, 0xd2, 0x47, 0x80, 0xe3, 0x84, 0x91, 0xf4, 0x78, 0x43, 0x64, 0x41, 
	                0x7b, 0x73, 0x99, 0x80, 0x42, 0x48, 0x00, 0xde, 0x00, 0x12, 0x88, 0x80, 0xdb, 0x51, 0x4a, 0x49, 
	                0x84, 0x43, 0xf6, 0x51, 0x90, 0x27, 0x21, 0xc9, 0xf8, 0xac, 0x00, 0x4d, 0xcd, 0x46, 0x09, 0x9d, 
	                0x15, 0x78, 0xe0, 0x00, 0x1e, 0x44, 0x2a, 0x51, 0x8c, 0xbc, 0xd3, 0xa3, 0x68, 0x8a, 0xd5, 0x3a, 
	                0x20, 0x79, 0xba, 0x4d, 0x71, 0x4c, 0x0b, 0x91, 0x98, 0x90, 0x7b, 0x2a, 0x42, 0xc5, 0x78, 0x7a, 
	                0xfc, 0xd5, 0x1b, 0x4b, 0x09, 0xa7, 0x27, 0x99, 0x38, 0x05, 0x01, 0xc2, 0x80, 0x39, 0x9c, 0x67, 
	                0xbb, 0x4e, 0x7f, 0x6c, 0x33, 0xdd, 0xed, 0x87, 0x55, 0xda, 0x5d, 0xb5, 0x56, 0x33, 0xc6, 0xf9, 
	                0xea, 0x60, 0x64, 0xcf, 0xa7, 0x41, 0xe0, 0x5c, 0x1c, 0xc4, 0xb2, 0x25, 0xa3, 0x89, 0x88, 0x8d, 
	                0x16, 0x00, 0xb5, 0xed, 0xa5, 0x22, 0x9d, 0x52, 0x41, 0x53, 0x8d, 0x92, 0x7f, 0x31, 0x51, 0x3f, 
	                0xa8, 0x00, 0x85, 0x8a, 0x71, 0x10, 0x92, 0x78, 0xc4, 0x59, 0x08, 0x39, 0x69, 0xa9, 0x38, 0x41, 
	                0x48, 0xf7, 0x40, 0x5a, 0x03, 0xd5, 0x3a, 0xf5, 0xe5, 0x9d, 0x33, 0x66, 0xc3, 0xd7, 0x1f, 0xef, 
	                0x94, 0xa0, 0x53, 0xea, 0xf4, 0x15, 0xb2, 0x1c, 0x40, 0x2d, 0xcf, 0xaf, 0xce, 0xe9, 0xd4, 0x7a, 
	                0x89, 0x09, 0xe6, 0xdd, 0xdb, 0x0e, 0xb8, 0x58, 0xa7, 0x60, 0x37, 0xfd, 0xf2, 0xfa, 0x2c, 0x4e, 
	                0x51, 0x87, 0x0d, 0xfc, 0x16, 0x72, 0x2a, 0x5f, 0xc0, 0x80, 0xf0, 0x54, 0xa7, 0xde, 0xfc, 0x15, 
	                0x8b, 0x9a, 0x36, 0x3a, 0x2c, 0x62, 0xfc, 0xd4, 0x8c, 0x31, 0xb7, 0xea, 0xd7, 0x26, 0xc4, 0xaf, 
	                0x75, 0xea, 0xdb, 0x8b, 0xff, 0x9b, 0x9b, 0x50, 0x7e, 0xfe, 0x15, 0xab, 0x17, 0x2f, 0x96, 0x96, 
	                0xbd, 0xaa, 0x87, 0xdd, 0x77, 0xa3, 0x77, 0xd3, 0x85, 0xf0, 0xe0, 0x58, 0xd5, 0xf6, 0x8c, 0xcd, 
	                0xc4, 0x63, 0x52, 0x12, 0x48, 0x46, 0x0f, 0x93, 0x5a, 0xe3, 0xea, 0x24, 0x67, 0x73, 0x63, 0xa0, 
	                0xdf, 0xdf, 0x3d, 0x67, 0xf6, 0xa9, 0xfc, 0xed, 0x08, 0xe3, 0x82, 0x57, 0x08, 0x35, 0x47, 0x68, 
	                0x9c, 0x01, 0x40, 0x87, 0x8b, 0xbd, 0x0c, 0xb3, 0xf4, 0xe1, 0x72, 0xd7, 0x54, 0x62, 0xfd, 0x40, 
	                0xed, 0x99, 0xa6, 0x7e, 0x2b, 0xe4, 0xb4, 0xc4, 0x62, 0x0d, 0x79, 0xae, 0x1b, 0xd7, 0xf4, 0x09, 
	                0xb7, 0xe1, 0x7c, 0x44, 0x09, 0x9a, 0xda, 0xff, 0x52, 0x6a, 0x3c, 0xe1, 0xc8, 0xd7, 0xbd, 0xbb, 
	                0xbe, 0x37, 0xfc, 0xd6, 0xd5, 0x4e, 0x3c, 0x40, 0x2a, 0x4b, 0x39, 0x1a, 0xbd, 0x2a, 0xcd, 0xc1, 
	                0x18, 0x59, 0x40, 0x62, 0x78, 0xec, 0x63, 0x19, 0x72, 0xf0, 0xcf, 0xf8, 0x38, 0xfa, 0x42, 0x3a, 
	                0xc8, 0x02, 0xec, 0x5b, 0xeb, 0x8d, 0xae, 0xf1, 0x45, 0xdd, 0x32, 0x98, 0x35, 0x3c, 0x9f, 0xa6, 
	                0x3d, 0xce, 0x13, 0xce, 0x94, 0x38, 0x87, 0x00, 0x8d, 0x85, 0xc4, 0x70, 0x17, 0x26, 0x0e, 0xa6, 
	                0x1e, 0x16, 0xcb, 0xbf, 0x52, 0xdf, 0x29, 0x63, 0xc4, 0xf6, 0x8c, 0x35, 0xba, 0xf2, 0xf9, 0x1f, 
	                0xbf, 0x73, 0x1f, 0x91, 0x1b, 0x9e, 0x24, 0x5e, 0x63, 0x22, 0x82, 0x23, 0x05, 0x19, 0xb9, 0x71, 
	                0x73, 0xdc, 0xcf, 0x05, 0x88, 0x94, 0x71, 0xdb, 0xdd, 0x48, 0x10, 0xd5, 0x55, 0xb3, 0x52, 0xc3, 
	                0x1b, 0x01, 0x94, 0x13, 0x74, 0x94, 0x3a, 0x80, 0x2f, 0x39, 0xe2, 0x75, 0x0e, 0xf2, 0xc6, 0x18, 
	                0xdc, 0x46, 0xfc, 0xf3, 0xea, 0x14, 0x80, 0xc1, 0xce, 0x24, 0xee, 0x72, 0xed, 0x94, 0xaf, 0xfb, 
	                0xa9, 0xaa, 0x4a, 0xe0, 0xd4, 0x22, 0xc6, 0xf0, 0x57, 0x1d, 0x8e, 0xd2, 0x90, 0xc6, 0x0c, 0xd3, 
	                0x9a, 0x53, 0xfb, 0xd6, 0xb7, 0xdd, 0x14, 0xd4, 0xbd, 0x41, 0xa7, 0x80, 0x7b, 0x23, 0xfe, 0x34, 
	                0x56, 0x0d, 0x96, 0x46, 0x02, 0xfe, 0xfd, 0xb2, 0x00, 0x5f, 0x01, 0x9c, 0xa0, 0x32, 0x39, 0xd7, 
	                0x90, 0xc2, 0x6c, 0xc7, 0x4e, 0x68, 0x88, 0x7d, 0x9f, 0x9b, 0xcf, 0xa7, 0xbe, 0xa0, 0xfc, 0x18, 
	                0x7d, 0x07, 0x5b, 0xa9, 0xbe, 0x56, 0x1f, 0x67, 0x1a, 0x4a, 0x91, 0x9c, 0x04, 0x38, 0x53, 0x6b, 
	                0x70, 0x68, 0x8f, 0xea, 0xf4, 0x34, 0x87, 0x7f, 0x6e, 0x82, 0xc3, 0xc1, 0xab, 0x40, 0xc4, 0x50, 
	                0x13, 0x0e, 0x33, 0x5d, 0x67, 0x7d, 0x01, 0x1f, 0xdb, 0xc0, 0x7f, 0xed, 0x87, 0x7f, 0xbc, 0x0f, 
	                0x75, 0xe0, 0xa5, 0xba, 0xc0, 0x84, 0x3d, 0x24, 0x04, 0xe0, 0xf1, 0x16, 0x41, 0x3b, 0x74, 0xd2, 
	                0x52, 0xc5, 0xf8, 0x7c, 0x12, 0xfb, 0xe4, 0x37, 0x5b, 0xfb, 0x57, 0x11, 0xa1, 0x18, 0x00, 0x00, 
	            };
            using (MemoryStream stream = new MemoryStream(bytes))
            using (GZipStream gzip = new GZipStream(stream, CompressionMode.Decompress))
            using (BinaryReader reader = new BinaryReader(gzip))
            {
                while (true)
                {
                    char ch = reader.ReadChar();
                    if (ch == '\0')
                        break;
                    int width = reader.ReadByte();
                    int height = reader.ReadByte();

                    bool[,] map = new bool[width, height];
                    for (int i = 0; i < width; i++)
                        for (int j = 0; j < height; j++)
                            map[i, j] = reader.ReadBoolean();
                    words_.Add(new CharInfo(ch, map));
                }
            }
        }

        public string Get_CaptchaCode(Bitmap bmp)
        {
            if (bmp == null)
            {
                throw new Exception("未能下载验证码图片！");
            }

            string result = string.Empty;
            int width = bmp.Width;
            int height = bmp.Height;
            bool[,] table = ToTable(bmp);
            int next = SearchNext(table, -1);

            while (next < width - 7)
            {
                MatchedChar matched = Match(table, next);
                if (matched.Rate > 0.6)
                {
                    result += matched.Char;
                    next = matched.X + 10;
                }
                else
                {
                    next += 1;
                }
            }
            if (result.Length != 4)
            {
                throw new Exception("识别失败！");
            }
            return result;
        }

        private string ReadTable(bool[,] table, int width, int height)
        {
            string result = string.Empty;
            int next = SearchNext(table, -1);

            while (next < width - 7)
            {
                MatchedChar matched = Match(table, next);
                if (matched.Rate > 0.6)
                {
                    result += matched.Char;
                    next = matched.X + 10;
                }
                else
                {
                    next += 1;
                }
            }
            return result;
        }

        /// <summary>
        /// 图片转矩阵，二值化、去干扰线、噪点。
        /// </summary>
        /// <param name="bmp"></param>
        /// <returns></returns>
        private bool[,] ToTable(Bitmap bmp)
        {
            bool[,] table = new bool[bmp.Width, bmp.Height];
            for (int i = 0; i < bmp.Width; i++)
                for (int j = 0; j < bmp.Height; j++)
                {
                    Color color = bmp.GetPixel(i, j);
                    if ((color.B + color.G) < 245)
                        table[i, j] = true; //(color.R + color.G + color.B < 500);
                }
            for (int i = 1; i < bmp.Width - 1; i++)
                for (int j = 1; j < bmp.Height - 1; j++)
                {
                    if (table[i, j])
                    {
                        int sum = 0;
                        if (table[i - 1, j - 1]) sum = sum + 1;
                        if (table[i - 1, j]) sum = sum + 1;
                        if (table[i - 1, j + 1]) sum = sum + 1;
                        if (table[i, j - 1]) sum = sum + 1;
                        if (table[i, j + 1]) sum = sum + 1;
                        if (table[i + 1, j - 1]) sum = sum + 1;
                        if (table[i + 1, j]) sum = sum + 1;
                        if (table[i + 1, j + 1]) sum = sum + 1;
                        if (sum < 2) table[i, j] = false;
                    }
                }
            return table;
        }

        /// <summary>
        /// 逐列扫描，找到第一个字母的起始列号。
        /// </summary>
        /// <param name="table"></param>
        /// <param name="start"></param>
        /// <returns></returns>
        private int SearchNext(bool[,] table, int start)
        {
            int width = table.GetLength(0);
            int height = table.GetLength(1);
            for (start++; start < width; start++)
                for (int j = 0; j < height; j++)
                    if (table[start, j])
                        return start;

            return start;
        }

        /// <summary>
        /// 精确匹配
        /// </summary>
        /// <param name="source"></param>
        /// <param name="target"></param>
        /// <param name="x0"></param>
        /// <param name="y0"></param>
        /// <returns></returns>
        private double FixedMatch(bool[,] source, bool[,] target, int x0, int y0)
        {
            double total = 0;
            double count = 0;
            int targetWidth = target.GetLength(0);
            int targetHeight = target.GetLength(1);
            int sourceWidth = source.GetLength(0);
            int sourceHeight = source.GetLength(1);
            int x, y;

            for (int i = 0; i < targetWidth; i++)
            {
                x = i + x0;
                if (x < 0 || x >= sourceWidth)
                    continue;
                for (int j = 0; j < targetHeight; j++)
                {
                    y = j + y0;
                    if (y < 0 || y >= sourceHeight)
                        continue;

                    if (target[i, j])
                    {
                        total++;
                        if (source[x, y])
                            count++;
                        else
                            count--;
                    }
                    else if (source[x, y])
                        count -= 0.55;
                }
            }

            return count / total;
        }

        /// <summary>
        /// 与字模进行模糊匹配
        /// </summary>
        /// <param name="source">当前图片的矩阵</param>
        /// <param name="target">字模矩阵</param>
        /// <param name="start">起始位</param>
        /// <returns></returns>
        private MatchedChar ScopeMatch(bool[,] source, bool[,] target, int start)
        {
            int targetWidth = target.GetLength(0);
            int targetHeight = target.GetLength(1);
            int sourceWidth = source.GetLength(0);
            int sourceHeight = source.GetLength(1);

            double max = 0;
            MatchedChar matched = new MatchedChar();
            for (int i = -2; i < 6; i++)
                for (int j = -3; j < sourceHeight - targetHeight + 5; j++)
                {
                    double rate = FixedMatch(source, target, i + start, j);
                    if (rate > max)//循环匹配所有字模，找到匹配率最高的那个
                    {
                        max = rate;
                        matched.X = i + start;
                        matched.Y = j;
                        matched.Rate = rate;
                    }
                }
            return matched;
        }

        /// <summary>
        /// 匹配
        /// </summary>
        /// <param name="source"></param>
        /// <param name="start"></param>
        /// <returns></returns>
        private MatchedChar Match(bool[,] source, int start)
        {
            MatchedChar best = null;
            foreach (CharInfo info in words_)
            {
                MatchedChar matched = ScopeMatch(source, info.Table, start);
                matched.Char = info.Char;
                if (best == null || best.Rate < matched.Rate)
                    best = matched;
            }
            return best;
        }

        /// <summary>
        /// 标准字模
        /// </summary>
        private class CharInfo
        {
            public char Char { get; private set; }
            public bool[,] Table { get; private set; }

            public CharInfo(char ch, bool[,] table)
            {
                Char = ch;
                Table = table;
            }
        }

        /// <summary>
        /// 识别出来的字节信息
        /// </summary>
        private class MatchedChar
        {
            public int X { get; set; }
            public int Y { get; set; }
            public char Char { get; set; }
            public double Rate { get; set; }
        }
    }
}
